UK-based Syrian Observatory for Human Rights reported that the Syrian army and pro-government forces have taken control of the road leading into rebel-held areas in Aleppo, effectively cutting off the rebels' main supply route.

Aleppo has been a major battlefield in Syria since 2010, with fierce fighting between rebel groups and regime forces.

Castello Road, the only route into the city's east, is now mostly in government hands, with pro-rebel neighborhoods in eastern Aleppo completely besieged, the observatory said. The road has been under constant bombardment from forces loyal to President Bashar al-Assad's government.